1. Field of the Invention
This invention relates to pressurized cleaning of flow conductors by an indexing, reciprocating and rotating apparatus utilizing high velocity fluid flow directed outward from the apparatus by means of nozzles.
2. Description of Related Art
In the past, various configurations of devices were used to attempt removal of foreign material from the interior of well tubing. This well tubing ranged from unperforated and perforated tubulars to slotted or wire-wrapped well liners. This well tubing often became plugged or coated with corrosion products, sediments and hydrocarbon deposits.
Wire brushes, scrapers, scratchers and cutters of various designs were among the first tools used to try to remove unwanted deposits. Some of these tools did not reach into the slots or perforations. Those that did had to have wires or feelers thin enough to enter the slot or perforation and were often too thin to provide much cleaning force. Then several types of washing tools were introduced to the industry utilizing pressurized jets of fluid to attempt to dislodge the undesired material from the well tubing. In the late thirties and early fifties (1955-59), the development of jet cleaning advanced from low velocity for use in cleaning and acidizing to utilization of abrasive particles suspended in the fluid for hydraulic fracturing of formations to enhance recovery of hydrocarbons. Abrasives were utilized for cleaning flow conductors, but results were less than favorable since the material of the flow conductors was eroded along with the foreign material plugging or coating the flow conductors.
In the early seventies, Stanley O. Hutchison received the following U.S. patents for High Pressure Jet Well Cleaning: U.S. Pat. Nos. 3,720,264; 3,811,499; 3,829,134; 3,850,241 and 4,088,191. These designs solved a lot of problems of prior devices by enabling the user to adjust the distance between the well tubing and the end of the jet nozzle. This distance, called the standoff distance, is considered critical to proper cleaning. Calculation of these distances is found in many technical publications. These devices, although an improvement in the art, still left many problems unsolved.
An attempt to solve several of these problems was made by Casper W. Zublin. Zublin, a licensee of the Hutchison patents, received U.S. Pat. Nos. Re. 31,495; 4,441,557; 4,442,899 and 4,518,041 (recently issued).
U.S. Pat. No. Re. 31,495 added a centralizer to help center the jet nozzles and provide a means to jar out of tight places in the tubing. This device is rotated by a power swivel at the surface.
U.S. Pat. No. 4,441,557 claims nozzles spaced so as to direct cleaning fluid onto the pipe in a certain pattern. The device is rotated at a constant speed by the power swivel at the surface.
U.S. Pat. No. 4,442,899 claims a method and system for a nonrotating device utilizing nozzles and alternating pressure to create an oscillating twisting force according to a certain formula.
U.S. Pat. No. 4,518,041 is formerly application No. 360,492. Per a copy of application No. 360,492, the inventor claims method and a system utilizing a device that is not rotated by the tubing at the surface. The device has nozzles which, like the device in U.S. Pat. No. 4,442,899, direct the flow of the cleaning fluid in such a manner as to tend to twist the tubing and the device. The amount of twist is varied by varying the pressure of the cleaning fluid supplied to the device. The system calls for some nozzles to be directionally coincidental with the horizontal axis. Other claims relate to a method of calculating the amount of twist. According to the applicant, these methods and systems are an effort to avoid the inefficiency of having a rotational rig at the surface to rotate the entire tubing. A device to do this is described but not claimed.